47results about How to "Reduce optical power density" patented technology

A mode-locked integrated semiconductor laser has a gain section and an absorption section that are based on quantum-confined active regions. The optical mode(s) in each section can be modeled as occupying a certain cross-sectional area, referred to as the mode cross-section. The mode cross-section in the absorber section is larger in area than the mode cross-section in the gain section, thus reducing the optical power density in the absorber section relative to the gain section. This, in turn, delays saturation of the absorber section until higher optical powers, thus increasing the peak power output of the laser.

The invention is suitable for the optical field, and provides a triply coated fiber, a pump combiner, a fiber grating and a fiber laser. A triply coated passive fiber comprises a fiber core, an innercladding layer covering outside the fiber core, an outer cladding layer covering outside the inner cladding layer, and a coating layer covering outside the outer cladding layer, the diameter of the fiber core is 10-50micrometer, the diameter of the inner cladding layer is 250-800micrometer, the diameter of the outer cladding layer is greater than the diameter of the inner cladding layer, the diameter of the outer cladding layer is 300-1000micrometer, or, the diameter of the inner cladding layer is 80-100micrometer, and the diameter of the outer cladding layer is 110-130micrometer. In the triply coated passive fiber, the outer cladding layer wrapping outside the inner cladding layer greatly reduces damage of pump light to the organic coating, the coating as a full reflection interface has ultrahigh damage threshold, so that the fiber laser is more reliable and stable.

In a semiconductor-laser device: a compressive-strain quantum-well active layer is made of Inx3Ga1-x3As1-y3Py3 (0<x3<=0.4 and 0<=y3<=0.1); tensile-strain barrier layers made of Inx2Ga1-2AS1-y2P1-y2 (0<=x2<0.49y2 and 0<y2<=0.4)are formed above and under the compressive-strain quantum-well active layer; and optical waveguide layers being made of either p-type or i-type In0.49Ga0.51P are formed above the upper tensile-strain barrier layer and under the lower tensile-strain barrier layer. Preferably, the absolute value of a sum of a first product and a second product is less than or equal to 0.25 nm, where the first product is a product of a strain and a thickness of said compressive-strain active layer, and the second product is a product of a strain of said lower and upper tensile-strain barrier layers and a total thickness of the lower and upper tensile-strain barrier layers.

A light input / output terminal module 100 comprises a jacket tube 110 and a flange 120. A glass portion 20 of the optical fiber is inserted in the center portion thereof. To efficiently remove the leaked light in a cladding 22 to the jacket tube 110, the jacket tube 110 is made of silica glass or the same material as that of the cladding 22. The jacket tube 110 is fixed by fusion splicing or adhesion to the cladding so as to integrally unify the jacket tube 110 and the cladding 22. The beam diameter at the fiber end portion is enlarged by an optical component which fusion bonds the tip end of the optical fiber to the coreless fiber so that the optical power density at the light input / output terminal module is reduced.

The invention provides a super-continuum spectrum optical fiber laser output apparatus and a laser system. The output apparatus comprises a laser transmission module, a returned-light processor, an optical stripper, a thermal processor and a packaging module; the laser transmission module comprises transmission optical fibers, an output end cap and a light beam focusing collimation part that are connected in sequence, and a photoelectric detector arranged on one side, close to the transmission optical fibers, of the output end cap; the photoelectric detector is used for monitoring the returned-light power at the output end of the output end cap; the returned-light processor is arranged on one side, connected with the transmission optical fibers, of the output end cap; the optical stripper is arranged on the transmission optical fibers close to the output end cap; the thermal process is arranged below the laser transmission module; and the packaging module is used for packaging the laser transmission module, the returned-light processor, the optical stripper and the thermal processor. According to the super-continuum spectrum optical fiber laser output apparatus, high-power and broadband spectrum stable laser output can be realized by performing special treatment on the output end of the whole apparatus, and by performing prompt processing on the returned light and thermal accumulation.

The present invention provides improved collimating lens assemblies (32) which include: a singlemode fiber (38) terminating in a distal end; a step-index multimode fiber (44) having a proximal end abutting to the singlemode fiber distal end, and having a distal end; a graded-index multimode fiber (45) having a proximal end abutting the step-index multimode fiber distal end, and having a distal end; and a collimating lens (34) longitudinally spaced from the graded-index multimode fiber distal end by an intermediate air gap (43), and operatively arranged to collimate light rays emanating from the graded-index multimode fiber distal end. The improved collimating lens assembly is characterized by the fact that there is no epoxy, silicone gel or index-matching material between the graded-index multimode fiber distal end and the collimating lens.

The invention provides a high-power optical fiber end cap and a manufacturing method thereof. The optical fiber end cap comprises a double-clad optical fiber, a core-free optical fiber and a quartz rod which are coaxially arranged; the quartz rod comprises a first cylindrical section, a circular table section and a second cylindrical section which are coaxially connected in sequence, the diameterof the first cylindrical section is smaller than that of the second cylindrical section; the double-clad optical fiber is connected with one end of the core-free optical fiber in a welding mode, and the other end of the core-free optical fiber is connected with one end of the first cylindrical section in a welding mode; the diameter of the cladding layer of the core-free optical fiber is larger than or equal to the diameter of the double-clad optical fiber; and the diameter of the cladding layer of the core-free optical fiber is smaller than or equal to the diameter of the first cylindrical section. The laser firstly passes through the core-free optical fiber, so that energy is expanded, and the light power density in the connecting place of the output end plane and the quartz rod is lowered; by selecting the proper length of the core-free optical fiber, the output light spot can be large enough when the laser outputs from the core-free optical fiber, so that the optical power densityon the output surface can be effectively reduced; and meanwhile, energy is not output from the side surface of the core-free optical fiber, and loss of energy is avoided.

A structure of high power edge emission laser diode that has plural mode extension sublayers with a chirp periodic distribution is provided. The Near Field Pattern (NFP) is an L shape, and the high intensity portion is nicely overlapped with the multi quantum wells. Furthermore, the low intensity portion will extend to the n-type cladding as it can as possible. Accordingly, the optical power density on the mirror surface of the high power edge emission laser diode is lower down and the vertical divergence angle is decreased, so as to prolong its lifetime.

The invention discloses a low-loss large-effective area single mode fiber and a manufacturing method of the low-loss large-effective area single mode fiber, and relates to the field of optical fibers. The low-loss large-effective area single mode fiber comprises a quartz glass cladding, an internal coating and an external coating, wherein the quartz glass cladding, the internal coating and the external coating are arranged in sequence from inside to outside; the inside of the quartz glass cladding comprises a first fiber core area, a second fiber core area, a third fiber core area, a fourth fiber core area and a refractive index concave cladding, wherein the first fiber core area, the second fiber core area, the third fiber core area, the fourth fiber core area and the refractive index concave cladding are arranged in sequence from inside to outside; the refractive index concave cladding is subjected to deposition through a PCVD process; the quartz glass cladding is manufactured through an OVD process or a sleeving process. According to the low-loss large-effective area single mode fiber and the manufacturing method of the low-loss large-effective area single mode fiber, the scattering loss of the low-loss large-effective area single mode fiber and the additional loss of the low-loss large-effective area single mode fiber in a bent state can be reduced; due to the fact that the spire distribution of fiber core basic mode electromagnetic field power is adjusted into flattop distribution, optical power density is reduced, the effective area of the low-loss large-effective area single mode fiber is enlarged, the nonlinearity of the low-loss large-effective area single mode fiber is reduced, the incident power of an optical fiber communication system is increased by 0.4-2.6 dB, and the low-loss large-effective area single mode fiber is suitable for mass production.

Embodiments described herein relate to an optical fiber stretch that may experience forward Raman amplification in which the peak optical signal power occurs at some distance from the transmitter. Smaller effective area optical fiber is used at a portion of the optical fiber stretch in which the optical signal power is increasing, while larger effective area optical fiber is used at a more remote stretch of the optical fiber stretch that experiences the peak optical signal power. Thus, the quality of the signal is better preserved since the larger effective area fiber reduces maximum optical signal density thereby reducing non-linear degradations on signal quality.

A cone-rod laser amplifier provided by the present invention belongs to the field of solid-state lasers, and includes a pump source, a seed source, a diverging lens, a cone-rod gain medium and a collimating lens arranged coaxially in sequence, the incident end face of the cone-rod gain medium and The exit end surface is coaxial and the spherical conical cap of the spherical cone is located at the focal point of the diverging lens, which satisfies:; The present invention also proposes a cone-rod gain medium group composed of multi-stage cone-rod gain media with a spherical conical profile , and the improved cone-rod laser amplifier with the cone-rod gain medium itself having the function of a diverging lens, so that the maximum efficiency of the seed light energy can be extracted from the energy storage of the reversed particle number in the cone-rod gain medium, so that the cone-rod laser amplifier can work close to saturation state; the cone-rod laser amplifier proposed by the present invention is small in size and simple in structure.